Property, Plant and Equipment, Net - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 1,900	$ 2,200	$ 9,600	$ 6,500
Property, plant and equipment, net	92,393		92,393		$ 96,014
Net book value of assets	4,400		4,400		7,400
Spare Parts [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,400		2,400		$ 2,500
Fixed Assets Dedicated to R&D Activities [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	$ 4,600		$ 4,600